The present invention relates to protective assemblies for lamps and more particularly to a protective shield assembly for fluorescent light tubes.
Heretofore, various proposals have been made for protecting or shielding fluorescent tubes. Typically, light shields are fabricated as elongated tubes of unbreakable plastic, such as polycarbonate. The shields are provided to protect plant personnel, for example, from injury in the event of fluorescent tube breakage. Such shields are also required for fluorescent tubes suspended over exposed food in restaurants and the like.
With such light shields, however, a problem is presented with "high output" and "very high output" fluorescent light units. Such fluorescent units draw electricity in the 800 to 1500 milliamperes range during normal operation. Excessive heat generation at the lamp cathodes may cause blistering, discoloration, cracking and/or charring of the plastic, tubular light shields. In order to prevent such damage to the tubes, it has been proposed to employ a heat shield or sink which extends towards the center of the tube and is supported adjacent the end of the tube at the high heat area. An example of one such heat shield may be found in U.S. Pat. No. 3,798,481, entitled FLUORESCENT LAMP HEAT SHIELD and issued on Mar. 19, 1974, to Pollara. The heat shield disclosed therein is a "window screen" wire mesh member defined by a plurality of woven longitudinally extending and circumferentially extending wires. The woven wire elements cross each other substantially perpendicularly. At each point of crossing, the wires are pressed into intimate contact to produce wire deformation. The weaving and flattening is apparently necessary to achieve the desired heat transfer characteristics.